1. Field of the Invention
This invention relates generally to techniques for performing data transfer operations, and relates more particularly to a system and method for effectively performing physical direct memory access operations.
2. Description of the Background Art
Implementing effective methods for transferring data between electronic devices is a significant consideration for designers and manufacturers of contemporary electronic devices. An electronic device in an electronic network may advantageously communicate with other electronic devices in the network to share data to thereby substantially increase the capabilities and versatility of individual devices in the electronic network. For example, an electronic network may be implemented in a home environment to enable flexible and beneficial sharing of data and device resources between various consumer electronic devices, such as personal computers, digital video disc (DVD) devices, digital set-top boxes for digital broadcasting, enhanced television sets, and audio reproduction systems.
Effectively managing data transfer operations in a network of electronic devices may create substantial challenges for designers of electronic networks. For example, enhanced demands for increased device functionality and performance during data transfer operations may require more system processing power and require additional hardware resources across the network. An increase in processing or hardware requirements may also result in a corresponding detrimental economic impact due to increased production costs and operational inefficiencies.
Network size is also a factor that affects the management of data transfer operations in an electronic network. Communications in an electronic network typically become more complex as the number of individual devices or nodes increases. Assume that a particular device on an electronic network is defined as a local device with local software elements, and other devices on the electronic network are defined as remote devices with remote software elements. Accordingly, a local software module on the local device may need to transfer data to various remote software elements on remote devices across the electronic network. However, successfully managing a substantial number of electronic devices across a network may provide significant benefits to a system user.
Furthermore, enhanced device capability to perform various advanced memory transfer operations may provide additional benefits to a system user, but may also place increased demands on the control and management of the various devices in the electronic network. For example, an enhanced electronic network that effectively accesses, processes, and displays digital television programming may benefit from efficient network communication techniques because of the large amount and complexity of the digital data involved.
In many systems, data transfer operations may occur under the control of a processor that initiates and coordinates bi-directional data transfer operations between a memory and a selected external device. However, detailed control of all data transfer operations by a system processor may significantly reduce the amount of processing time available to perform other important tasks.
Direct memory access (DMA) is a data transfer technique that substantially reduces the amount of processing time required from a system processor to perform a data transfer operation. In practice, direct memory access allows an external device to read from, or write to, a memory without significant intervention by the system processor. Typically, the processor may then continue performing other processing tasks.
Due to growing demands on system processor resources and substantially increasing data magnitudes, it is apparent that developing new and effective methods for transferring data is a matter of importance for the related electronic technologies. Therefore, for all the foregoing reasons, implementing effective methods for transferring data between electronic devices remains a significant consideration for designers, manufacturers, and users of contemporary electronic devices.
In accordance with the present invention, a system and method are disclosed for effectively performing physical direct memory access (DMA) operations. In one embodiment, initially, a DMA engine of a target device in an electronic network preferably receives a packet from an initiator device that is also in the electronic network. The DMA engine then preferably analyzes a header of the received packet to determine how to successfully perform the DMA operation.
If a designated field of the header requests a physical DMA operation, then a notifier module preferably examines a notification enable field to determine whether to provide a notification to target device software about the occurrence of the physical DMA operation. The notifier module thus permits the DMA engine to selectively filter the notifications of physical DMA operations to thereby eliminate time-consuming analysis of unnecessary notifications by the target device software.
In one embodiment, if the notification enable field authorizes the notifier module to notify the device software about the occurrence of the physical DMA operation, then the notifier module preferably forwards the header from the current packet to the device software as a notification. In alternate embodiments, the notifier module may similarly provide various other types of notification to the device software. The DMA engine also preferably utilizes information from the header to successfully perform the requested DMA operation.
In accordance with the present invention, the device software is therefore notified of the physical DMA operation. In various device applications, this timely notification may facilitate optimal utilization of device resources. For example, in a case where an extended series of packets are being transferred by physical DMA for subsequent processing by the device software, an initial notification of the physical DMA operation may advantageously permit the device software to perform an overlapping processing procedure that begins at the time of the initial notification, rather than waiting until the entire DMA data transfer operation is complete. The present invention therefore facilitates and promotes intelligent functioning of device software, and thus efficiently implements a system and method for effectively performing physical DMA operations.